Hsic communication system and method

ABSTRACT

A High Speed Inter Chip (HSIC) system and method for minimizing power consumption by controlling the state of the HSIC module through a control line are provided. The method between a host and a slave includes transitioning, when no communication request exists for a first reference time in an active state where all functions of the HSIC modules are enabled, to a suspend state where least functions used for maintaining a communication link of the HSIC modules and transitioning, when no communication request exists for a second reference time in the suspend state, to a power-off state where the HSIC modules turn off The HSIC communication method and apparatus are advantageous to minimize the electric current consumption of the HSIC consumption system.

PRIORITY

This application claims the benefit under 35 U.S.C. §119(a) of a Koreanpatent application filed on Mar. 23, 2011 in the Korean IntellectualProperty Office and assigned Serial No. 10-2011-0025665, the entiredisclosure of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a High Speed Inter Chip (HSIC)communication system and method. More particularly, the presentinvention relates to an HSIC system and method that is capable ofminimizing power consumption by controlling the state of the HSIC modulethrough a control line.

2. Description of the Related Art

With the advancement of information communication and semiconductortechnologies, the popularity and use of mobile terminals have increasedrapidly. More particularly, the latest mobile terminals have evolved toan extent where it is possible to support the mobile convergenceblending various communication capabilities into a single logical set ofservices. More specifically, the latest mobile communication terminalsare configured to support various supplementary functions, such as abroadcast playback function (e.g., Digital Multimedia Broadcasting (DMB)and Digital Video Broadcasting (DVB)), an audio playback function (e.g.,a Motion Pictures Expert Group (MPEG-1 or MPEG-2) Audio Layer-3 (MP3), aphotographing function, a data communication function, and Internetaccess functions, as well as voice communication and messaging functionsof the related art.

In order to support the diverse functions, it has become normal formobile communication terminals to be equipped with multiple chips.Typically, the communication between the chips is implemented by meansof a memory (e.g., a Dual Ported Random Access Memory (DPRAM) and ONEDynamic RAM (ONEDRAM)) or a serial interface (e.g., a Service ProviderInterface (SPI), a Secure Digital Input Output (SDIO), a Mobile IndustryProcessor Interface (MIPI), a Host Integration Server (HIS), and thelike). More recently, the latest mobile terminals adopt a High SpeedInter Chip (HSIC) interface for high data rate in inter-chipcommunication. HSIC is based on Universal Serial Bus (USB) technologyand supports a data rate up to 480 Mbps. However, the USBtechnology-based HSIC has a drawback of high electric currentconsumption. Accordingly, the mobile terminal equipped with the HSICconsumes battery resources at a fast rate.

Therefore, a need exists for an HSIC communication system and methodthat is capable of minimizing electric current consumption bycontrolling the state of the HSIC module through a control interface.

SUMMARY OF THE INVENTION

Aspects of the present invention are to address at least theabove-mentioned problems and/or disadvantages and to provide at leastthe advantages described below. Accordingly, an aspect of the presentinvention is to provide a High Speed Inter Chip (HSIC) communicationsystem and method that is capable of minimizing electric currentconsumption by controlling the state of the HSIC module through acontrol interface.

Another aspect of the present invention is to provide an HSICcommunication system and method that is capable of reducing the rate ofbattery consumption of the mobile terminal by minimizing the electriccurrent consumption of the HSIC communication system.

In accordance with an aspect of the present invention, an HSICcommunication system is provided. The system includes a host including afirst HSIC module wherein the host controls, when no communicationrequest exists for a first reference time in an active state where allfunctions of the first HSIC module are enabled, the first HSIC module totransition to a suspend state where least functions used for maintaininga communication link of the first HSIC module and send a suspend commandto the second HSIC module, and transition, when no communication requestexists for a second reference time in the suspend state, to a power-offstate where the first HSIC module turns off and enable a host activeline for controlling turn-on/off of the second HSIC module, and a slavewith a second HSIC module wherein the slave controls, when the suspendcommand is received, the second HSIC module to transition to the suspendstate and turns off, when the host active line is enabled, the secondHSIC module to transition to the power-off state.

In accordance with another aspect of the present invention, an HSICcommunication method between a host and a slave is provided. The methodincludes transitioning, when no communication request exists for a firstreference time in an active state where all functions of the HSICmodules are enabled, to a suspend state where least functions used formaintaining a communication link of the HSIC modules, and transitioning,when no communication request exists for a second reference time in thesuspend state, to a power-off state where the HSIC modules turn off

Other aspects, advantages, and salient features of the invention willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainexemplary embodiments of the present invention will be more apparentfrom the following description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a schematic diagram illustrating a configuration of a HighSpeed Inter Chip (HSIC) communication system according to an exemplaryembodiment of the present invention;

FIG. 2 is a state transition diagram illustrating transition of a stateof an HSIC module according to an exemplary embodiment of the presentinvention;

FIGS. 3A and 3B illustrate procedures of state transition of HSICmodules from an active state to a suspend state according to anexemplary embodiment of the present invention;

FIG. 4 illustrates procedures of state transition of HSIC modules from asuspend state to a power-off state according to an exemplary embodimentof the present invention;

FIGS. 5A and 5B illustrate procedures of state transition of HSICmodules from a suspend state to an active state according to anexemplary embodiment of the present invention; and

FIGS. 6A and 6B illustrate procedures of state transition of HSICmodules from a power-off state to an active state according to anexemplary embodiment of the present invention.

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features, andstructures.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of exemplaryembodiments of the invention as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the embodiments described hereincan be made without departing from the scope and spirit of theinvention. In addition, descriptions of well-known functions andconstructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of theinvention. Accordingly, it should be apparent to those skilled in theart that the following description of exemplary embodiments of thepresent invention is provided for illustrative purposes only and not forthe purpose of limiting the invention as defined by the appended claimsand their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

By the term “substantially” it is meant that the recited characteristic,parameter, or value need not be achieved exactly, but that deviations orvariations, including for example, tolerances, measurement error,measurement accuracy limitations and other factors known to those ofskill in the art, may occur in amounts that do not preclude the effectthe characteristic was intended to provide.

In the following description, the term “active state” denotes the statewhere the High Speed Inter Chip (HSIC) module is activated forcommunication between chips, the term “suspended state” denotes thestate where only the least function for maintaining the communicationlink of the HSIC is activated, and the term “power-off state” is thestate where the power supply to the HSIC is blocked. If data transfer isrequested in the power-off state, an initial process should be performedto power on the HSIC module and establish the communication link.

FIGS. 1 through 6B, discussed below, and the various exemplaryembodiments used to describe the principles of the present disclosure inthis patent document are by way of illustration only and should not beconstrued in any way that would limit the scope of the disclosure. Thoseskilled in the art will understand that the principles of the presentdisclosure may be implemented in any suitably arranged communicationssystem. The terms used to describe various embodiments are exemplary. Itshould be understood that these are provided to merely aid theunderstanding of the description, and that their use and definitions inno way limit the scope of the invention. Terms first, second, and thelike are used to differentiate between objects having the sameterminology and are in no way intended to represent a chronologicalorder, unless where explicitly stated otherwise. A set is defined as anon-empty set including at least one element.

FIG. 1 is a schematic diagram illustrating a configuration of an HSICcommunication system according to an exemplary embodiment of the presentinvention, and FIG. 2 is a state transition diagram illustratingtransition of a state of an HSIC module according to an exemplaryembodiment of the present invention.

Referring to FIGS. 1 and 2, the HSIC communication system includes ahost 100 and a slave 200. The host 100 includes a first HSIC module 10for high speed inter-chip communication, and the slave 200 includes asecond HSIC module 20.

As aforementioned, the HSIC communication interface is the communicationinterface based on the Universal Serial Bus (USB) 2.0 standard for highspeed data transfer. Recently, HSIC is a promising communicationinterface due to the advantage of its high speed data rate.

The host 100 is the main chip of the HSIC communication system and canbe an Application Processor (AP). The slave is the sub chip of the HSICcommunication system and can be a Communication Processor (CP)responsible for processing communication.

The HSIC communication system according to an exemplary embodiment ofthe present invention can further include a data line (DATA) for datatransfer according to the HSIC communication interface standard, a hostwake-up line (HOST WAKE-UP) to request activation of the first HSICmodule 10 in addition to a strobe line (STROBE), a slave wake-up line(SLAVE WAKE-UP) to request activation of the second HSIC module 20, ahost suspend request line (HOST SUSPEND REQ) to request transition tothe suspend state, and a host active line (HOST ACTIVE) for controllingpower on/off of the second HSIC module 20. These lines are establishedby connecting the General Purpose Input/Output (GPIO) nodes of the host100 and slave 200.

The HSIC communication system can control the states of the first HSICmodule 10 and the second HSIC module 20 to minimize the powerconsumption. More specifically, the HSIC communication system cancontrol the first and second HSIC modules 10 and 20 to operate in one ofan Active State (L0), a Suspend State (L2), and a Power-off State (L3)as shown in FIG. 2. The active state (L0) is the state where all thefunctions of the first and second HSIC modules 10 and 20 are activated.The suspend state (L2) is the state where some of the functions of thefirst and second HSIC modules 10 and 20 reduce power consumption when nodata is transmitted while the least functions are activated formaintaining the HSIC communication link. The power-off state (L3) is thestate where the power supply to the first and second HSIC modules 10 and20 is blocked.

Referring to FIG. 2, if no communication request (e.g., a data transferrequest) is detected for a predefined first reference time (T1) in theactive state (L0), the state of the first and second HSIC modules 10 and20 can transition from the active state (L0) to the suspend state (L2)as denoted by reference number 201. If no communication request (e.g.,data transfer request) is detected for a predefined second time (T2) inthe suspend state (L2), the state of the first and second HSIC modules10 and 20 can transition from the suspend state (L2) to the power-offstate (L3) as denoted by reference number 203. If the communicationrequest is detected in the suspend state (L2), the state of the firstand second HSIC modules 10 and 20 can transition from the suspend state(L2) to the active state (L0) as denoted by reference number 205. If thecommunication request is detected in the power-off state (L3), the stateof the first and second HSIC modules 10 and 20 can transition from thepower-off state to the active state (L0) as denoted by reference number207. The first and second reference times T1 and T2 can be set to thesame value or different values.

In order to transition from the active state (L0) to the power-off state(L3), the state of the first and second HSIC modules 10 and 20 has totransition to the suspend state (L2) first. This is to prevent the datafrom being lost in the middle of transmission due to the abruptpower-off to the first and second HSIC modules 10 and 20.

Exemplary embodiments of the present invention can be applied to all thetypes of terminals supporting high data transfer between inner chips.More particularly, exemplary embodiments of the present invention areadvantageous to the power-constraint mobile devices, such as a mobilecommunication terminal, a tablet Personal Computer (PC), a PortableMultimedia Player (PMP), a navigation terminal, a Smartphone, anelectronic book, an electronic dictionary, a laptop computer, a netbook,and an Ultra Mobile Personal Computer (UMPC).

The configuration of the HSIC communication system and state transitionof the HSIC modules have been described schematically. The statetransition of the HSIC module is described below.

FIGS. 3A and 3B illustrate procedures of state transition of HSICmodules from an active state to a suspend state according to anexemplary embodiment of the present invention.

Referring to FIGS. 1 through 3B, if there is no communication requestdetected in the active state (L0) for the first reference time, theslave 200 or the host 100 can request transition to the suspend state(L2). FIG. 3A is the signaling diagram illustrating the slave-triggeredstate transition from the active state to the suspend state, and FIG. 3Bis the signaling diagram illustrating the host-triggered statetransition from the active state to the suspend state.

Referring to FIG. 3A, if no communication request (e.g., a data transferrequest) is detected for the first reference time (T1) after thecommunication has completed in the active state, the slave 200 of theHSIC communication system can send the host 100 a signal requesting fortransition to the suspend state (L2) in step 301. At this time, theslave 200 can enable a host suspend request line (Host-Suspend-Req).Here, to enable means to change the signal from low state to high stateon the signal line. If the host suspend request line is enabled, thehost 100 controls the first HSIC module 10 to transition from the activestate (L0) to the suspend state (L2) in step 303 and send a suspendcommand (HSIC-Suspend) to the second HSIC module 20 of the slave 200according to the HSIC communication standard in step 305. Morespecifically, the first HSIC module 10 switches the data line (DATA) toLow state and the strobe line (STROBE) to High state.

Upon receipt of the HSIC-Suspend, the second HSIC module 200 of theslave transitions to the suspend state (L2) in step 307. Thereafter, theslave 200 sends the host 100 a host suspend request (Host Suspend-Req)to disable the host suspend request line in step 309. In this manner,the state of the first and second HSIC modules 10 and 20 transition fromthe active state (L0) to the suspend state (L2). As described above, theslave 200 can request the host 100 for the transition to the suspendstate (L2) to reduce power consumption of the HSIC communication system.

Referring to FIG. 3B, if no communication request is detected for thefirst reference time (T1) after the communication has completed in theactive state, the host 100 of the HSIC communication system controls thefirst HSIC module 10 to transition to the suspend state (L2) in step 331and sends the suspend command (HSIC-Suspend) to the second HSIC module20 of the slave 200 in step 333. More specifically, the first HSICmodule 10 switches the data line (DATA) to Low state and the strobe line(STROBE) to high state.

Upon receipt of the HSIC-Suspend, the second HSIC module 20 of the slave200 transitions to the suspend state (L2) in step 335. In this manner,the first and second HSIC modules 10 and 20 transition from the activestate (L0) to the suspend state (L2).

FIG. 4 illustrates procedures of state transition of HSIC modules from asuspend state to a power-off state according to an exemplary embodimentof the present invention.

Referring to FIGS. 1, 2, and 4, if there is no communication request(e.g., a data transfer request) detected in the suspended state (L2) forthe second reference time, the host 100 turns off (or blocks) the powerto the first HSIC module 10 to transition to the power-off state (L3) instep 401. Thereafter, the host 100 sends the slave 200 a signal(Host-Active) requesting for transition to the power-off state (L3) instep 403. For this purpose, the host 100 can disable the host activeline controlling power on/off of the second HSIC module 20. Upon receiptof the power-off state transition request signal, the slave 200 turnsoff (or blocks) the power to the second HSIC module 20 to transition tothe power-off state (L2) in step 405. In this manner, the first andsecond HSIC modules 10 and 20 can transition from the suspend state (L2)to the power-off state (L3). Since the first and second HSIC modules 10and 20 transition to the power-off state when there is no communicationbetween the host 100 and the slave 200, the HSIC communication system iscapable of reducing the unnecessary power consumption for maintainingthe communication between the host 100 and slave 200.

FIGS. 5A and 5B illustrate procedures of state transition of HSICmodules from a suspend state to an active state according to anexemplary embodiment of the present invention.

Referring to FIGS. 1, 2, 5A, and 5B, if a communication request (e.g., adata transfer request) is detected in the host 100 or the slave 200after the first and second HSIC modules 10 and 20 have transitioned tothe suspend module (L2), the host 100 and the slave 200 can control thefirst and second HSIC modules 10 and 20 to transition to the activestate (L0). FIG. 5A is the signaling diagram illustrating theslave-triggered state transition from the suspend state to the activestate, and FIG. 5B is the signaling diagram illustrating thehost-triggered state transition from the suspend state to the activestate.

Referring to FIG. 5A, if a communication request is detected in thesuspend state (L2), the slave 200 sends a host wakeup request signal(Host-Wakeup) to the first HSIC module 10 to request activation of thefirst HSIC module 10 in step 501. For this purpose, the slave 200 canenable the host wakeup line (Host-Wakeup). Upon receipt of the hostwakeup request signal, the host 100 resumes the suspended functions ofthe first HSIC module 10 to transition the first HSIC module 10 from thesuspended state (L2) to the active state (L0) in step 503 and sends afunction resume request command (HSIC-Resume) to the second HSIC module20 of the slave 200 according to the HSIC communication standard in step505. More specifically, the first HSIC module 10 switches the data line(DATA) to High state and the strobe line (STROBE) to Low state.

Upon receipt of the communication resume command, the second HSIC module20 of the slave 200 resumes its suspended functions to transition to theactive state (L0) in step 507. After the second HSIC module 20 hastransitioned to the active state (L0), the slave 200 can disable thehost wake up line (Host-Wakeup) in step 509. Once both the first andsecond HSIC modules 10 and 20 transition to the active state (L0), theslave 200 transmits the requested data to the host 100 by means of thesecond HSIC module 20.

Referring to FIG. 5B, if a communication request is detected in thesuspend state (L2), the host 100 sends a slave wakeup request signal(Slave-Wakeup) to the slave 200 to request activation of the second HSICmodule 20 in step 531. For this purpose, the host 100 can enable theslave wakeup line (Slave-Wakeup). Upon receipt of the slave wakeuprequest signal, the slave 200 sends the host 100 a host resume requestsignal to request activation of the first HSIC module 10 in step 533.For this purpose, the slave 200 can enable the host wakeup line(Host-Wakeup). Upon receipt of the host wakeup request signal, the host100 controls the first HSIC module 10 to resume its suspended functionsto transition from the suspend state (L2) to the active state (L0) instep 535 and send a communication resume command (HSIC-Resume) to thesecond HSIC module 20 of the slave 200 in step 537.

Upon receipt of the communication resume command, the second HSIC module20 resumes its suspended functions to transition from the suspend state(L2) to the active state (L0) in step 539. After the second HSIC module20 has transitioned to the active state (L0), the slave 200 can disablethe host wakeup line (Host-Wakeup) in step 541. The host 100 can alsodisable the slave wakeup line (Slave-Wakeup) in step 543. Once both thefirst and second HSIC modules 10 and 20 transition to the active state(L0), the host 100 can transmit the request data to the slave 200 bymeans of the first HSIC module 10.

FIGS. 6A and 6B illustrate procedures of state transition of HSICmodules from a power-off state to an active state according to anexemplary embodiment of the present invention.

Referring to FIGS. 1, 2, 6A, and 6B, if a communication request isdetected in the host 100 or the slave 200 while the first and secondHSIC modules 10 and 20 are in the power-off state (L3), the host 100 andthe slave 200 can control the first and second HSIC modules 10 and 20 totransition to the active state (L0). FIG. 6A is the signaling diagramillustrating the slave-triggered state transition from the power-offstate to the active state, and FIG. 6B is the signaling diagramillustrating the host-triggered state transition from the power-offstate to the active state.

Referring to FIG. 6A, if the communication request is detected in thepower-off state (L3), the slave 200 sends a HSIC module activationrequest signal (Host-Wakeup) to the host 100 in step 601. For thispurpose, the slave 200 can enable the host wakeup line (Host-Wakeup).Upon receipt of the HSIC module activation request signal, the host 100turns on the power of the first HSIC module 10 to transition from thepower-off state (L3) to the active state (L0) in step 603 and sends anHSIC module power-on request signal to the slave 200 in step 605. Forthis purpose, the host 100 can enable the host active line(Host-Active).

Upon receipt of the HSIC module power-on request signal, the slave 200turns on the second HSIC module 20 to transition from the power-offstate (L3) to the active state (L0) in step 607. Once the second HSICmodule 20 enters the active state (L0), the slave 200 can disable thehost wakeup line (Host-Wakeup) in step 609. After transitioning to theactive state (L0), the first and second HSIC modules 10 and 20 performthe initialization process to establish the communication link accordingto the HSIC communication standard in step 611. Since the initializationprocedure is specified in the HSIC communication standard, detaileddescription thereon is omitted herein. Once the initializationcompletes, the slave 200 can transmit the request data to the host 100by means of the second HSIC module 20.

Referring to FIG. 6B, if a communication request is detected in thepower-off state (L3), the host 100 sends an HSIC module activationrequest signal (Slave-Wakeup) to the slave 200 in step 631. For thispurpose, the host 100 can enable the slave wakeup line (Slave-Wakeup).Upon receipt of the HSIC module activation request signal, the slave 200sends a HSIC activation request signal (Host-Wakeup) to the host 100 instep 633. For this purpose, the slave 200 can enable the host wakeupline (Host-Wakeup). Upon receipt of the HSIC activation request signal,the host 100 turns on the power of the first HSIC module 10 totransition from the power-off state (L3) to the active state (L0) instep 635 and sends an HSIC activation request signal to the slave 200 instep 637. For this purpose, the host 100 can enable the host active line(Host-Active).

Upon receipt of the HSIC activation request signal, the slave 200 turnson the power of the second HSIC module 20 to transition from thepower-off state (L3) to the active state (L0) in step 639. Once thesecond HSIC module 20 enters the active state (L0), the slave 200 candisable the host wakeup line (Host-Wakeup) in step 641. In addition, thehost 100 can disable the slave wakeup line (Slave-Wakeup) in step 643.

Once both the first and second HSIC modules 10 and 20 power on, thefirst and second HSIC modules 10 and 20 perform the initializationprocess to establish a communication link according to the HSICcommunication standard in step 645. After the initialization processcompletes, the host 100 can transmit the requested data to the slave 200by means of the first HSIC module 10.

The above-described exemplary HSIC communication method of the presentinvention can be implemented in the form of computer-executable programcommands and stored in a computer-readable storage medium. The computerreadable storage medium can store the program commands, data files, anddata structures in individual or combined forms. The program commandsrecorded in the storage medium can be designed and implemented for thepresent invention or used by those skilled in the computer softwarefield.

The computer-readable storage medium includes a magnetic media, such asa floppy disk and a magnetic tape, an optical media including a CompactDisc (CD) Read Only Memory (ROM) and a Digital Video Disc (DVD) ROM, amagneto-optical media, such as a floptical disk, and the hardware devicedesigned for storing and executing program commands, such as ROM, RandomAccess Memory (RAM), and flash memory. The program commands include thelanguage code executable by computers using the interpreter as well asthe machine language codes created by a compiler. The aforementionedhardware device can be implemented with one or more software modules forexecuting the operations of the present invention.

As described above, the exemplary HSIC communication system and methodof the present invention controls the HSIC modules to transition to thesuspend state when no data communication occurs over a predefined periodin the active state and to the power-off state when no datacommunication occurs over a predefined time in the suspend state,resulting in minimization of power consumption of the HSIC communicationsystem. In addition, the HSIC communication and method of the presentinvention is capable of reducing the rate of battery consumption of themobile terminal adopting the improved HSIC communication system andmethod.

While the invention has been shown and described with reference tocertain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims and their equivalents.

1. A High Speed Inter Chip (HSIC) communication system, the systemcomprising: a host including a first HSIC module wherein the hostcontrols, when no communication request exists for a first referencetime in an active state where all functions of the first HSIC module areenabled, the first HSIC module to transition to a suspend state whereleast functions used for maintaining a communication link of the firstHSIC module and send a suspend command to the second HSIC module, andtransition, when no communication request exists for a second referencetime in the suspend state, to a power-off state where the first HSICmodule turns off and enable a host active line for controllingturn-on/off of the second HSIC module; and a slave including a secondHSIC module wherein the slave controls, when the suspend command isreceived, the second HSIC module to transition to the suspend state andturns off, when the host active line is enabled, the second HSIC moduleto transition to the power-off state.
 2. The system of claim 1, whereinthe slave enables, when no communication request exists for the firstreference time in the active state, a host suspend request line torequest the host for transition to the suspend state of the first HSICmodule, controls, when the suspend command is received from the host,the second HSIC module to transition to the suspend state, and disables,when the second HSIC module transitions to the suspend state, the hostsuspend request line.
 3. The system of claim 1, wherein the hostenables, when a communication request to the slave is detected in thepower-off state, a slave wakeup line to request activation of the secondHSIC module, turns on, when a host wakeup line is enabled to requestactivation of the first HSIC module, the power to the first HSIC module,enables the host active line, disables, when the host wakeup line isdisabled, the slave wakeup line, and performs initial process forestablishing a communication link with the slave.
 4. The system of claim1, wherein the slave enables, when a communication request to the hostis detected in the power-off state, a host wakeup line to requestactivation of the first HSIC module, turns on, when the host active linefor controlling power-on/off of the second HSIC module is enabled, powerto the second HSIC module in order for the second HSIC module totransition to the active state, disables the host wakeup line, andperforms initial process for establishing a communication link with thehost.
 5. The system of claim 1, wherein the host enables, when acommunication request to the slave is detected in the suspend state, aslave wakeup line to request activation of the second HSIC module,resumes, when a host wakeup line is enabled to request activation of thefirst HSIC module, suspended functions of the first HSIC module, sends acommunication resume command for resuming the functions of the secondHSIC module, and disables, when the disable of host wakeup link isdetected, the slave wakeup link.
 6. The system of claim 1, wherein theslave enables, when a communication request to the host is detected inthe suspend state, a host wakeup line to request activation of the firstHSIC module, resumes, when a communication resume command to resume thefunctions of the second HSIC module from the first HSIC module,suspended functions of the second HSIC module to transition to theactive state, and disables the host wakeup line.
 7. The system of claim1, wherein the host is an application processor.
 8. The system of claim1, wherein the slave is a communication processor.
 9. A High Speed InterChip (HSIC) communication method between a host and a slave, the methodcomprising: transitioning, when no communication request exists for afirst reference time in an active state where all functions of the HSICmodules are enabled, to a suspend state where least functions used formaintaining a communication link of the HSIC modules; and transitioning,when no communication request exists for a second reference time in thesuspend state, to a power-off state where the HSIC modules turn off 10.The method of claim 9, wherein the transitioning to the suspend statecomprises: enabling, when no communication request is detected for thefirst reference time in the active state, a host suspend request line torequest the first HSIC module to transition to the suspend state;controlling, at the host, the first HSIC module to transition to thesuspend state; transmitting, at the first HSIC module, a suspend commandto the second HSIC module of the slave; transitioning, at the secondHSIC module, to the suspend state upon receipt of the suspend command;and disabling, at the slave, the host suspend request line.
 11. Themethod of claim 9, wherein the transitioning to the power-off statecomprises: turning off, when no communication request is detected forthe second reference time in the suspend state, the first HSIC module ofthe host; disabling, at the host, a host active line for controllingpower-on/off of the second HSIC module of the slave; and turning off, atthe slave, power to the second HSIC module.
 12. The method of claim 9,further comprising: enabling, at the slave when a communication requestis detected in the suspend state, a host wakeup line to requestactivation of the first HSIC module of the host; controlling, at thehost, the first HSIC module to activate functions to transition to theactive state and to transmit a communication resume command to thesecond HSIC module of the slave; transitioning, at the second HSICmodule, to the active state by activating the functions; and disabling,at the slave, the host wakeup line.
 13. The method of claim 9, furthercomprising: enabling, at the host when a communication request isdetected in the suspend state, a slave wakeup line to request activationof the second HSIC module of the slave; enabling, at the slave, a hostwakeup line to request activation of the first HSIC module of the host;controlling, at the host, the first HSIC module to resume functions totransition to the active state and transmit a communication resumecommand to the second HSIC module; transitioning, at the second HSICmodule, to the active state by resuming the functions; and disabling, atthe host, the slave wakeup line.
 14. The method of claim 9, furthercomprising: enabling, at the slave when a communication request isdetected in the power-off state, a host wakeup line to requestactivation of the first HSIC module of the host; controlling, at thehost, the first HSIC module to power on to transition to the activestate and enable a host active line to control power-on/off of thesecond HSIC module of the slave; controlling, at the slave, the secondHSIC module to power on to transition to the active state; disabling, atthe slave, the host wakeup line; and performing initialization processto establish an HSIC communication link between the host and the slave.15. The method of claim 9, further comprising: enabling, at the hostwhen a communication request is detected in the power-off state, a slavewakeup line to request activation of the second HSIC module of theslave; enabling, at the slave, a host wakeup line to request activationof the first HSIC module of the host; controlling, at the host, thefirst HSIC module to power on to transition to the active state andenables a host active line to control power-on/off of the second HSICmodule; controlling, at the slave, the second HSIC module to power on totransition to the active state; disabling, at the slave, the host wakeupline; disabling, at the host, the slave wakeup line; and performinginitialization process to establish an HSIC communication link betweenthe host and the slave.